Remove `Builder` abstractions for gradients

15 files changed, 163 insertions, 209 deletions

diff --git a/core/src/background.rs b/core/src/background.rs
index 6af33c3e..347c52c0 100644
--- a/core/src/background.rs
+++ b/core/src/background.rs
@@ -1,4 +1,5 @@
-use crate::{Color, Gradient};
+use crate::gradient::{self, Gradient};
+use crate::Color;
 
 /// The background of some element.
 #[derive(Debug, Clone, Copy, PartialEq)]
@@ -16,14 +17,14 @@ impl From<Color> for Background {
     }
 }
 
-impl From<Color> for Option<Background> {
-    fn from(color: Color) -> Self {
-        Some(Background::from(color))
+impl From<Gradient> for Background {
+    fn from(gradient: Gradient) -> Self {
+        Background::Gradient(gradient)
     }
 }
 
-impl From<Gradient> for Option<Background> {
-    fn from(gradient: Gradient) -> Self {
-        Some(Background::Gradient(gradient))
+impl From<gradient::Linear> for Background {
+    fn from(gradient: gradient::Linear) -> Self {
+        Background::Gradient(Gradient::Linear(gradient))
     }
 }
diff --git a/core/src/gradient.rs b/core/src/gradient.rs
index 54bb86a4..e19622fb 100644
--- a/core/src/gradient.rs
+++ b/core/src/gradient.rs
@@ -1,8 +1,8 @@
-//! For creating a Gradient.
-pub use linear::Linear;
-
+//! Colors that transition progressively.
 use crate::{Color, Radians};
 
+use std::cmp::Ordering;
+
 #[derive(Debug, Clone, Copy, PartialEq)]
 /// A fill which transitions colors progressively along a direction, either linearly, radially (TBD),
 /// or conically (TBD).
@@ -14,19 +14,11 @@ pub enum Gradient {
 }
 
 impl Gradient {
-    /// Creates a new linear [`linear::Builder`].
-    ///
-    /// This must be defined by an angle (in [`Degrees`] or [`Radians`])
-    /// which will use the bounds of the widget as a guide.
-    pub fn linear(angle: impl Into<Radians>) -> linear::Builder {
-        linear::Builder::new(angle.into())
-    }
-
     /// Adjust the opacity of the gradient by a multiplier applied to each color stop.
     pub fn mul_alpha(mut self, alpha_multiplier: f32) -> Self {
         match &mut self {
             Gradient::Linear(linear) => {
-                for stop in linear.color_stops.iter_mut().flatten() {
+                for stop in linear.stops.iter_mut().flatten() {
                     stop.color.a *= alpha_multiplier;
                 }
             }
@@ -36,6 +28,12 @@ impl Gradient {
     }
 }
 
+impl From<Linear> for Gradient {
+    fn from(gradient: Linear) -> Self {
+        Self::Linear(gradient)
+    }
+}
+
 #[derive(Debug, Default, Clone, Copy, PartialEq)]
 /// A point along the gradient vector where the specified [`color`] is unmixed.
 ///
@@ -50,84 +48,58 @@ pub struct ColorStop {
     pub color: Color,
 }
 
-pub mod linear {
-    //! Linear gradient builder & definition.
-    use crate::gradient::{ColorStop, Gradient};
-    use crate::{Color, Radians};
-    use std::cmp::Ordering;
-
-    /// A linear gradient that can be used as a [`Background`].
-    #[derive(Debug, Clone, Copy, PartialEq)]
-    pub struct Linear {
-        /// How the [`Gradient`] is angled within its bounds.
-        pub angle: Radians,
-        /// [`ColorStop`]s along the linear gradient path.
-        pub color_stops: [Option<ColorStop>; 8],
-    }
+/// A linear gradient.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct Linear {
+    /// How the [`Gradient`] is angled within its bounds.
+    pub angle: Radians,
+    /// [`ColorStop`]s along the linear gradient path.
+    pub stops: [Option<ColorStop>; 8],
+}
 
-    /// A [`Linear`] builder.
-    #[derive(Debug)]
-    pub struct Builder {
-        angle: Radians,
-        stops: [Option<ColorStop>; 8],
+impl Linear {
+    /// Creates a new [`Linear`] gradient with the given angle in [`Radians`].
+    pub fn new(angle: impl Into<Radians>) -> Self {
+        Self {
+            angle: angle.into(),
+            stops: [None; 8],
+        }
     }
 
-    impl Builder {
-        /// Creates a new [`Builder`].
-        pub fn new(angle: Radians) -> Self {
-            Self {
-                angle,
-                stops: [None; 8],
+    /// Adds a new [`ColorStop`], defined by an offset and a color, to the gradient.
+    ///
+    /// Any `offset` that is not within `0.0..=1.0` will be silently ignored.
+    ///
+    /// Any stop added after the 8th will be silently ignored.
+    pub fn add_stop(mut self, offset: f32, color: Color) -> Self {
+        if offset.is_finite() && (0.0..=1.0).contains(&offset) {
+            let (Ok(index) | Err(index)) =
+                self.stops.binary_search_by(|stop| match stop {
+                    None => Ordering::Greater,
+                    Some(stop) => stop.offset.partial_cmp(&offset).unwrap(),
+                });
+
+            if index < 8 {
+                self.stops[index] = Some(ColorStop { offset, color });
             }
-        }
-
-        /// Adds a new [`ColorStop`], defined by an offset and a color, to the gradient.
-        ///
-        /// Any `offset` that is not within `0.0..=1.0` will be silently ignored.
-        ///
-        /// Any stop added after the 8th will be silently ignored.
-        pub fn add_stop(mut self, offset: f32, color: Color) -> Self {
-            if offset.is_finite() && (0.0..=1.0).contains(&offset) {
-                let (Ok(index) | Err(index)) =
-                    self.stops.binary_search_by(|stop| match stop {
-                        None => Ordering::Greater,
-                        Some(stop) => stop.offset.partial_cmp(&offset).unwrap(),
-                    });
-
-                if index < 8 {
-                    self.stops[index] = Some(ColorStop { offset, color });
-                }
-            } else {
-                log::warn!(
-                    "Gradient color stop must be within 0.0..=1.0 range."
-                );
-            };
-
-            self
-        }
+        } else {
+            log::warn!("Gradient color stop must be within 0.0..=1.0 range.");
+        };
 
-        /// Adds multiple [`ColorStop`]s to the gradient.
-        ///
-        /// Any stop added after the 8th will be silently ignored.
-        pub fn add_stops(
-            mut self,
-            stops: impl IntoIterator<Item = ColorStop>,
-        ) -> Self {
-            for stop in stops.into_iter() {
-                self = self.add_stop(stop.offset, stop.color)
-            }
+        self
+    }
 
-            self
+    /// Adds multiple [`ColorStop`]s to the gradient.
+    ///
+    /// Any stop added after the 8th will be silently ignored.
+    pub fn add_stops(
+        mut self,
+        stops: impl IntoIterator<Item = ColorStop>,
+    ) -> Self {
+        for stop in stops.into_iter() {
+            self = self.add_stop(stop.offset, stop.color)
         }
 
-        /// Builds the linear [`Gradient`] of this [`Builder`].
-        ///
-        /// Returns `BuilderError` if gradient in invalid.
-        pub fn build(self) -> Gradient {
-            Gradient::Linear(Linear {
-                angle: self.angle,
-                color_stops: self.stops,
-            })
-        }
+        self
     }
 }
diff --git a/examples/solar_system/src/main.rs b/examples/solar_system/src/main.rs
index 42606e3f..d9e660d7 100644
--- a/examples/solar_system/src/main.rs
+++ b/examples/solar_system/src/main.rs
@@ -10,8 +10,9 @@ use iced::application;
 use iced::executor;
 use iced::theme::{self, Theme};
 use iced::widget::canvas;
+use iced::widget::canvas::gradient;
 use iced::widget::canvas::stroke::{self, Stroke};
-use iced::widget::canvas::{Cursor, Gradient, Path};
+use iced::widget::canvas::{Cursor, Path};
 use iced::window;
 use iced::{
     Application, Color, Command, Element, Length, Point, Rectangle, Renderer,
@@ -209,13 +210,12 @@ impl<Message> canvas::Program<Message> for State {
 
                 let earth = Path::circle(Point::ORIGIN, Self::EARTH_RADIUS);
 
-                let earth_fill = Gradient::linear(
+                let earth_fill = gradient::Linear::new(
                     Point::new(-Self::EARTH_RADIUS, 0.0),
                     Point::new(Self::EARTH_RADIUS, 0.0),
                 )
                 .add_stop(0.2, Color::from_rgb(0.15, 0.50, 1.0))
-                .add_stop(0.8, Color::from_rgb(0.0, 0.20, 0.47))
-                .build();
+                .add_stop(0.8, Color::from_rgb(0.0, 0.20, 0.47));
 
                 frame.fill(&earth, earth_fill);
 
diff --git a/examples/toast/src/main.rs b/examples/toast/src/main.rs
index 9d859258..515218e7 100644
--- a/examples/toast/src/main.rs
+++ b/examples/toast/src/main.rs
@@ -226,7 +226,7 @@ mod toast {
             };
 
             container::Appearance {
-                background: pair.color.into(),
+                background: Some(pair.color.into()),
                 text_color: pair.text.into(),
                 ..Default::default()
             }
diff --git a/examples/tour/src/main.rs b/examples/tour/src/main.rs
index 630b6359..a40f0f33 100644
--- a/examples/tour/src/main.rs
+++ b/examples/tour/src/main.rs
@@ -1,3 +1,4 @@
+use iced::gradient;
 use iced::theme;
 use iced::theme::Palette;
 use iced::widget::{
@@ -7,8 +8,7 @@ use iced::widget::{
 use iced::widget::{Button, Column, Container, Slider};
 use iced::{alignment, widget, Theme};
 use iced::{
-    Color, Degrees, Element, Font, Gradient, Length, Radians, Renderer,
-    Sandbox, Settings,
+    Color, Degrees, Element, Font, Length, Radians, Renderer, Sandbox, Settings,
 };
 
 pub fn main() -> iced::Result {
@@ -734,23 +734,25 @@ impl widget::button::StyleSheet for CustomButtonStyle {
     fn active(&self, _style: &Self::Style) -> widget::button::Appearance {
         match self {
             CustomButtonStyle::Primary => widget::button::Appearance {
-                background: Gradient::linear(Degrees(270.0))
-                    .add_stop(0.0, Palette::LIGHT.primary)
-                    .add_stop(1.0, Color::from_rgb8(54, 80, 168))
-                    .build()
-                    .into(),
+                background: Some(
+                    gradient::Linear::new(Degrees(270.0))
+                        .add_stop(0.0, Palette::LIGHT.primary)
+                        .add_stop(1.0, Color::from_rgb8(54, 80, 168))
+                        .into(),
+                ),
                 text_color: Color::WHITE,
                 border_radius: 5.0,
                 ..Default::default()
             },
             CustomButtonStyle::Secondary => widget::button::Appearance {
-                background: Gradient::linear(Radians(
-                    3.0 * std::f32::consts::PI / 2.0,
-                ))
-                .add_stop(0.0, Color::from_rgb8(194, 194, 194))
-                .add_stop(1.0, Color::from_rgb8(126, 126, 126))
-                .build()
-                .into(),
+                background: Some(
+                    gradient::Linear::new(Radians(
+                        3.0 * std::f32::consts::PI / 2.0,
+                    ))
+                    .add_stop(0.0, Color::from_rgb8(194, 194, 194))
+                    .add_stop(1.0, Color::from_rgb8(126, 126, 126))
+                    .into(),
+                ),
                 text_color: Color::WHITE,
                 border_radius: 5.0,
                 ..Default::default()
diff --git a/graphics/src/geometry.rs b/graphics/src/geometry.rs
index 88997288..729c3d44 100644
--- a/graphics/src/geometry.rs
+++ b/graphics/src/geometry.rs
@@ -12,7 +12,7 @@ pub use stroke::{LineCap, LineDash, LineJoin, Stroke};
 pub use style::Style;
 pub use text::Text;
 
-pub use crate::core::gradient::{self, Gradient};
+pub use crate::gradient::{self, Gradient};
 
 use crate::Primitive;
 
diff --git a/graphics/src/geometry/fill.rs b/graphics/src/geometry/fill.rs
index 6aa1f28b..b773c99b 100644
--- a/graphics/src/geometry/fill.rs
+++ b/graphics/src/geometry/fill.rs
@@ -1,8 +1,8 @@
 //! Fill [crate::widget::canvas::Geometry] with a certain style.
-use iced_core::Color;
-
 pub use crate::geometry::Style;
-use crate::Gradient;
+
+use crate::core::Color;
+use crate::gradient::{self, Gradient};
 
 /// The style used to fill geometry.
 #[derive(Debug, Clone)]
@@ -50,6 +50,15 @@ impl From<Gradient> for Fill {
     }
 }
 
+impl From<gradient::Linear> for Fill {
+    fn from(gradient: gradient::Linear) -> Self {
+        Fill {
+            style: Style::Gradient(Gradient::Linear(gradient)),
+            ..Default::default()
+        }
+    }
+}
+
 /// The fill rule defines how to determine what is inside and what is outside of
 /// a shape.
 ///
diff --git a/graphics/src/gradient.rs b/graphics/src/gradient.rs
index 21bcd2c6..3e88d9de 100644
--- a/graphics/src/gradient.rs
+++ b/graphics/src/gradient.rs
@@ -1,10 +1,11 @@
-//! A gradient that can be used as a [`Fill`] for a mesh.
+//! A gradient that can be used as a [`Fill`] for some geometry.
 //!
 //! For a gradient that you can use as a background variant for a widget, see [`Gradient`].
 //!
 //! [`Gradient`]: crate::core::Gradient;
-use crate::core::Point;
-pub use linear::Linear;
+use crate::core::gradient::ColorStop;
+use crate::core::{Color, Point};
+use std::cmp::Ordering;
 
 #[derive(Debug, Clone, PartialEq)]
 /// A fill which linearly interpolates colors along a direction.
@@ -16,104 +17,72 @@ pub enum Gradient {
     Linear(Linear),
 }
 
-impl Gradient {
-    /// Creates a new linear [`linear::Builder`].
-    ///
-    /// The `start` and `end` [`Point`]s define the absolute position of the [`Gradient`].
-    pub fn linear(start: Point, end: Point) -> linear::Builder {
-        linear::Builder::new(start, end)
+impl From<Linear> for Gradient {
+    fn from(gradient: Linear) -> Self {
+        Self::Linear(gradient)
     }
 }
 
-pub mod linear {
-    //! Linear gradient builder & definition.
-    use crate::Gradient;
-    use iced_core::gradient::ColorStop;
-    use iced_core::{Color, Point};
-    use std::cmp::Ordering;
+/// A linear gradient that can be used in the style of [`Fill`] or [`Stroke`].
+///
+/// [`Fill`]: crate::geometry::Fill;
+/// [`Stroke`]: crate::geometry::Stroke;
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct Linear {
+    /// The absolute starting position of the gradient.
+    pub start: Point,
 
-    /// A linear gradient that can be used in the style of [`Fill`] or [`Stroke`].
-    ///
-    /// [`Fill`]: crate::geometry::Fill;
-    /// [`Stroke`]: crate::geometry::Stroke;
-    #[derive(Debug, Clone, Copy, PartialEq)]
-    pub struct Linear {
-        /// The absolute starting position of the gradient.
-        pub start: Point,
+    /// The absolute ending position of the gradient.
+    pub end: Point,
 
-        /// The absolute ending position of the gradient.
-        pub end: Point,
+    /// [`ColorStop`]s along the linear gradient direction.
+    pub stops: [Option<ColorStop>; 8],
+}
 
-        /// [`ColorStop`]s along the linear gradient direction.
-        pub color_stops: [Option<ColorStop>; 8],
+impl Linear {
+    /// Creates a new [`Builder`].
+    pub fn new(start: Point, end: Point) -> Self {
+        Self {
+            start,
+            end,
+            stops: [None; 8],
+        }
     }
 
-    /// A [`Linear`] builder.
-    #[derive(Debug)]
-    pub struct Builder {
-        start: Point,
-        end: Point,
-        stops: [Option<ColorStop>; 8],
-    }
+    /// Adds a new [`ColorStop`], defined by an offset and a color, to the gradient.
+    ///
+    /// Any `offset` that is not within `0.0..=1.0` will be silently ignored.
+    ///
+    /// Any stop added after the 8th will be silently ignored.
+    pub fn add_stop(mut self, offset: f32, color: Color) -> Self {
+        if offset.is_finite() && (0.0..=1.0).contains(&offset) {
+            let (Ok(index) | Err(index)) =
+                self.stops.binary_search_by(|stop| match stop {
+                    None => Ordering::Greater,
+                    Some(stop) => stop.offset.partial_cmp(&offset).unwrap(),
+                });
 
-    impl Builder {
-        /// Creates a new [`Builder`].
-        pub fn new(start: Point, end: Point) -> Self {
-            Self {
-                start,
-                end,
-                stops: [None; 8],
+            if index < 8 {
+                self.stops[index] = Some(ColorStop { offset, color });
             }
-        }
+        } else {
+            log::warn!("Gradient: ColorStop must be within 0.0..=1.0 range.");
+        };
 
-        /// Adds a new [`ColorStop`], defined by an offset and a color, to the gradient.
-        ///
-        /// Any `offset` that is not within `0.0..=1.0` will be silently ignored.
-        ///
-        /// Any stop added after the 8th will be silently ignored.
-        pub fn add_stop(mut self, offset: f32, color: Color) -> Self {
-            if offset.is_finite() && (0.0..=1.0).contains(&offset) {
-                let (Ok(index) | Err(index)) =
-                    self.stops.binary_search_by(|stop| match stop {
-                        None => Ordering::Greater,
-                        Some(stop) => stop.offset.partial_cmp(&offset).unwrap(),
-                    });
-
-                if index < 8 {
-                    self.stops[index] = Some(ColorStop { offset, color });
-                }
-            } else {
-                log::warn!(
-                    "Gradient: ColorStop must be within 0.0..=1.0 range."
-                );
-            };
-
-            self
-        }
-
-        /// Adds multiple [`ColorStop`]s to the gradient.
-        ///
-        /// Any stop added after the 8th will be silently ignored.
-        pub fn add_stops(
-            mut self,
-            stops: impl IntoIterator<Item = ColorStop>,
-        ) -> Self {
-            for stop in stops.into_iter() {
-                self = self.add_stop(stop.offset, stop.color)
-            }
+        self
+    }
 
-            self
+    /// Adds multiple [`ColorStop`]s to the gradient.
+    ///
+    /// Any stop added after the 8th will be silently ignored.
+    pub fn add_stops(
+        mut self,
+        stops: impl IntoIterator<Item = ColorStop>,
+    ) -> Self {
+        for stop in stops.into_iter() {
+            self = self.add_stop(stop.offset, stop.color)
         }
 
-        /// Builds the linear [`Gradient`] of this [`Builder`].
-        ///
-        /// Returns `BuilderError` if gradient in invalid.
-        pub fn build(self) -> Gradient {
-            Gradient::Linear(Linear {
-                start: self.start,
-                end: self.end,
-                color_stops: self.stops,
-            })
-        }
+        self
     }
 }
diff --git a/graphics/src/lib.rs b/graphics/src/lib.rs
index ae338936..b44fd603 100644
--- a/graphics/src/lib.rs
+++ b/graphics/src/lib.rs
@@ -23,13 +23,13 @@
 #![cfg_attr(docsrs, feature(doc_cfg))]
 mod antialiasing;
 mod error;
-mod gradient;
 mod transformation;
 mod viewport;
 
 pub mod backend;
 pub mod compositor;
 pub mod damage;
+pub mod gradient;
 pub mod primitive;
 pub mod renderer;
 
diff --git a/src/lib.rs b/src/lib.rs
index b81da394..804be045 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -188,6 +188,7 @@ pub use style::theme;
 
 pub use crate::core::alignment;
 pub use crate::core::event;
+pub use crate::core::gradient;
 pub use crate::core::{
     color, Alignment, Background, Color, ContentFit, Degrees, Gradient, Length,
     Padding, Pixels, Point, Radians, Rectangle, Size, Vector,
diff --git a/style/src/theme.rs b/style/src/theme.rs
index 1b47e2f9..c9835ca3 100644
--- a/style/src/theme.rs
+++ b/style/src/theme.rs
@@ -371,7 +371,7 @@ impl container::StyleSheet for Theme {
 
                 container::Appearance {
                     text_color: None,
-                    background: palette.background.weak.color.into(),
+                    background: Some(palette.background.weak.color.into()),
                     border_radius: 2.0,
                     border_width: 0.0,
                     border_color: Color::TRANSPARENT,
@@ -896,7 +896,7 @@ impl scrollable::StyleSheet for Theme {
                 let palette = self.extended_palette();
 
                 scrollable::Scrollbar {
-                    background: palette.background.weak.color.into(),
+                    background: Some(palette.background.weak.color.into()),
                     border_radius: 2.0,
                     border_width: 0.0,
                     border_color: Color::TRANSPARENT,
@@ -923,7 +923,7 @@ impl scrollable::StyleSheet for Theme {
                     let palette = self.extended_palette();
 
                     scrollable::Scrollbar {
-                        background: palette.background.weak.color.into(),
+                        background: Some(palette.background.weak.color.into()),
                         border_radius: 2.0,
                         border_width: 0.0,
                         border_color: Color::TRANSPARENT,
diff --git a/tiny_skia/src/backend.rs b/tiny_skia/src/backend.rs
index dd1adbd8..9495d2fc 100644
--- a/tiny_skia/src/backend.rs
+++ b/tiny_skia/src/backend.rs
@@ -463,7 +463,7 @@ fn into_gradient<'a>(
     let Gradient::Linear(linear) = gradient;
     let (start, end) = linear.angle.to_distance(&bounds);
     let stops: Vec<tiny_skia::GradientStop> = linear
-        .color_stops
+        .stops
         .into_iter()
         .flatten()
         .map(|stop| {
diff --git a/tiny_skia/src/geometry.rs b/tiny_skia/src/geometry.rs
index 100db0b0..ee347c73 100644
--- a/tiny_skia/src/geometry.rs
+++ b/tiny_skia/src/geometry.rs
@@ -233,7 +233,7 @@ pub fn into_paint(style: Style) -> tiny_skia::Paint<'static> {
             Style::Gradient(gradient) => match gradient {
                 Gradient::Linear(linear) => {
                     let stops: Vec<tiny_skia::GradientStop> = linear
-                        .color_stops
+                        .stops
                         .into_iter()
                         .flatten()
                         .map(|stop| {
diff --git a/wgpu/src/geometry.rs b/wgpu/src/geometry.rs
index e26d9278..b8a75c33 100644
--- a/wgpu/src/geometry.rs
+++ b/wgpu/src/geometry.rs
@@ -631,7 +631,7 @@ fn pack_gradient(gradient: &Gradient) -> [f32; 44] {
             let mut pack: [f32; 44] = [0.0; 44];
             let mut offsets: [f32; 8] = [2.0; 8];
 
-            for (index, stop) in linear.color_stops.iter().enumerate() {
+            for (index, stop) in linear.stops.iter().enumerate() {
                 let [r, g, b, a] = stop
                     .map_or(crate::core::Color::default(), |s| s.color)
                     .into_linear();
diff --git a/wgpu/src/layer.rs b/wgpu/src/layer.rs
index b3ee4739..08c0004a 100644
--- a/wgpu/src/layer.rs
+++ b/wgpu/src/layer.rs
@@ -317,7 +317,7 @@ fn pack_gradient(gradient: &core::Gradient, bounds: Rectangle) -> [f32; 44] {
         core::Gradient::Linear(linear) => {
             let mut pack: [f32; 44] = [0.0; 44];
 
-            for (index, stop) in linear.color_stops.iter().enumerate() {
+            for (index, stop) in linear.stops.iter().enumerate() {
                 let [r, g, b, a] =
                     stop.map_or(Color::default(), |s| s.color).into_linear();